Four previous studies from my laboratory have confirmed the existence for the vast majority of middle-class infants of spontaneously developed gestures which symbolically represent objects, requests, or conditions (e.g., panting for "dog"; hand-rotating as in turning a door knob for "want out",; arms raised for "big"). These gestures are a phenomenon of early language acquisition and are used communicatively in ways directly parallel to verbal words. Their status as symbols is based upon their spontaneous application by the infant in a wide variety of appropriate contexts. Although identifiable in almost all infants, impressive individual differences exist in their number and longevity. Of particular importance to the present study are the consistently obtained positive correlations between the tendency to develop these types of gestures and the rate of verbal vocabulary acquisition. The proposed study represents a logical next step in the programmatic exploration of this phenomenon. Having documented the existence of symbolic gesturing and described its correlates for children experiencing typical language acquisition environments, our attention in the present study turns toward assessing the impact of purposefully promoting this type of gesturing. Only in this way will we be able to explore the reasons for the positive correlations described above and evaluate specific hypotheses about the relation between symbolic gesturing and development in other domains, most notably cognitive development and parent-child relations. Comparisons will be made among three groups of infants. Parents of infants in the sign Training Group will be trained to encourage symbolic gesturing. In order to control for the increased levels of parent-child interaction that would inevitably result from such training, parents of a second group of infants, the Verbal Training Group will be trained to encourage verbal labeling. Finally, a third group will function as a control for participation in a longitudinal study of language development. Parents of infants in this Non-Intervention Group will be unaware of any special focus on language. Biweekly interviews from 11 months to 24 months will be conducted with parents in the two training groups in order to evaluate compliance with training instruction and to obtain accurate information about gestural and language development. These data will be augmented by laboratory assessments of verbal development, symbolic play, spatial memory, and parent-child relations for all three groups at 15-, 19-, and 24-months. In comparison to subjects in these latter two groups, it is hypothesized that children in the Sign Training Group will acquire verbal vocabulary at a faster rate, will show greater gains in two cognitive domains characterized by mental representation skills (symbolic play and memory for spatial location), and will engender in their parents higher levels of satisfaction with certain aspects of parent-child relations. The information gained will be important to theories of symbol development in general and language acquisition in particular. In addition, the results will enable us to provide informed advice to parents about the potential advantages and disadvantages of encouraging this type of gesturing in their infants.